Publications

Abstract: This paper investigates the effects of carpooling organization on the propensity to carpool. We test whether pre-trip planning and the use of a platform influence the choice of carpooling over driving alone and public transport. In a stated choice experiment, we collected responses from 3600 residents of the Lyon urban area, France. Our econometric results suggest that platforms increase individual willingness to carpool, and that the effect of the platform is stronger for passengers than for drivers. We illustrate these results with a stylized social welfare analysis, which reveals a significant contradiction between what would be needed to make carpooling beneficial from a welfare perspective – passengers should be subsidized – and the current pricing schemes, which subsidize mainly drivers. 

(official link)

Abstract: The present case study aims to enrich the discussion on Conventional Rail (CR) interventions, investigating two types of solutions, a frequency increase and a new station construction, in two different contexts, respectively, characterised by high and low demands. The area of investigation is Regione Lombardia (Italy). We combine a Benefit-Cost Analysis (BCA) and a Life Cycle Assessment (LCA) to estimate economic and environmental viability. We find different performances according to the scenarios. In the high-demand area, a Benefit Cost Ratio (BCR) larger than 1 is observed in both interventions, while in the low-demand area, the BCR is significantly lower than 1. For the emissions, the implementation of the interventions shows almost a net balance of zero between the emissions saved and the additional emissions produced. Sensitivity analyses varying the critical variables (i.e., demand diverted, investment costs, and emission factors) are performed. The diverted demand results in being critical to improve both performances, whereas a mutually beneficial approach that combines environmental and transport policies is essential to reduce transport emissions. The following study contributes to academia by comparing the expected effects of different railway interventions in a CR system, using a combined economic and environmental assessment for their evaluation. 

(official link)

Abstract: Subsidization of urban public transportation systems is often motivated by economies of scale and second-best considerations such as an underpriced road alternative. We model a public transit line subject to frictions between users (in-vehicle crowding), users and vehicles (boarding and alighting delays), and vehicles (congestion). We derive the profit- and welfare-maximizing provisions of supply. We show that if demand exceeds a first threshold, the system enters a congested regime and service frequency decreases. Beyond a second threshold, the strong deterioration of service quality causes the transit line to operate under diseconomies of scale, calling for a Pigouvian tax instead of a subsidy. This finding, which goes against Mohring’s classical rule (1972), holds with an untolled road alternative, provided that the network structure remains constant. We estimate the model for the London Piccadilly line and find evidence of substantial diseconomies of scale during the morning peak, adding up to −1.49 £/trip for the observed provision of service quality (-0.61 £/trip at optimum). These results question current subsidy policies for the busiest transit lines.

(official link)

Abstract: This paper investigates the productive efficiency of French regional rail operators. Benefiting from unique databases, we use a panel stochastic frontier model to measure and explain the productive efficiency. We consider the regional monopoly nature of these operators by introducing specific contract-related variables. Technical efficiency level ranges from 59 to 98 per cent, revealing a high degree of heterogeneity in productive performance between regional operators. Factors related to the societal environment, characteristics of the rail system and contractual design are significantly correlated with the technical efficiency. Policy implications of these results are substantial for both public authorities and rail operators. 

(official link)

Abstract: We conduct a discrete choice experiment on 1556 solo-driving commuters in Lyon, France to estimate the values of end-to-end travel time (VoTT) of commuting trips in the presence of a HOV-lane for four modes: Solo Driver, Carpool Driver, Carpool Passenger and Public Transport. Using discrete choice models, we find a strong heterogeneity in VoTT across modes and individuals. The analysis of individual heterogeneity distinguishes four behavior patterns: reluctant to mode change (20% of our sample), preferring the three alternative modes over solo driver (35%), preferring public transport (12%) and preferring driver modes whether solo or carpool (32%). We find that current solo drivers are more likely to switch to carpooling as a driver rather than as a passenger. As suggested by our simulations aimed at marginally changing mode shares, carpool passenger will be the scarce resource if one wants to decrease car traffic by stimulating carpooling for commuting trips. 

(official link)

Abstract: Long-distance carpooling is an emerging mode in France and Europe, but little is known about monetary values of this mode attributes in transport economics. We conducted a discrete choice experiment to identify and measure the values of attributes of long-distance transport modes for a trip as a driver and as a passenger, with a special focus on carpooling. Around 1.700 French individuals have been surveyed. We use discrete mixed logit models to estimate the probability of mode choice. We find that the value of travel time for a driver who carpools is on average 13% higher than the value of travel time when driving alone in his/her car. The average value of travel time for a carpool trip as passenger is around 26 euros per hour, 60% higher than for a train trip and 20% higher than for a bus trip. Moreover, our study confirms a strong preference for driving solo over taking carpoolers in one’s car. We also show that individuals traveling as carpool passenger incur a “discomfort” cost of on average 4.5 euros per extra passenger in the same vehicle. Finally, we identify robust socio-economic effects affecting the probability of carpooling, especially gender effects. When they drive a car, females are less likely to carpool than male, but they prefer to carpool two passengers over only one passenger.

(pdf and official link)

Abstract: This paper studies the efficient pricing of medium-distance passenger rail in Europe. Current fares and frequencies are compared with three alternatives: first-best where road congestion is internalised; second-best where no road tolls are implemented; and third-best where a maximum rail deficit is also imposed. We find that second-best fares depend strongly on the non-internalised road congestion and on the price elasticity of the passengers, complicating the derivation of a national or regional fare structure. Second-best achieves a significant share of the first-best benefits, but adding a budget constraint makes second-best solutions difficult to implement for some corridors.

(pdf and official link)

Abstract: We model trip-timing decisions of rail transit users who trade off crowding costs and disutility from traveling early or late. With no fare or a uniform fare, ridership is too concentrated on timely trains. Marginal-cost-pricing calls for time-dependent fares that smooth train loads and generate more revenue than an optimal uniform fare. The welfare gains from time-dependent fares are unlikely to increase as ridership grows. However, imposing time-dependent fares raises the benefits of expanding capacity by either adding trains or increasing train capacity. We illustrate these results by calibrating the model to the Paris RER A transit system.

(working paper and official link)

Abstract: Crowding on public transport (PT) is a major issue for commuters around the world. Nevertheless, economists have rarely investigated the causes of crowding discomfort. Furthermore, most evidence on the costs of PT crowding is based on trade-offs between crowding, travel time and money. First, this paper assesses discomfort with PT crowding at various density levels across heterogeneous individuals using a different methodology. Based on a survey of 1000 Paris PT users, the negative relationship of in-vehicle density on reported satisfaction is similar to previous studies investigating PT crowding costs and stable across most individual characteristics. We also find a sensitive increase in crowding costs over users’ income. Second, we investigate the causes of this discomfort effect. We identify three key drivers: (a) dissatisfaction with standing and not being seated; (b) less opportunities to make use of the time during the journey; (c) the physical closeness of other travelers per se.

(pdf and official link)

Abstract: We consider the modeling of a bi-modal competitive network involving a public transport mode, which may be unreliable, and an alternative mode. Commuters select a transport mode and their arrival time at the station when they use public transport. The public transport reliability set by the public transport firm at the competitive equilibrium increases with the alternative mode fare, via a demand effect. This is reminiscent of the Mohring Effect. The study of the optimal service quality shows that often, public transport reliability and thereby patronage are lower at equilibrium compared to first-best social optimum. The paper provides some public policy insights.

(pdf and official link)

Abstract: Land-Use and transport interaction models today take an important role as decision-making tools, especially in a context marked by the reinforcement of economical, energy and environmental constraints. If the estimation of transport demand and accessibilities in these models depends on densities, these densities are often viewed as exogenous. This paper intends to render them endogenous by measuring the effect of accessibilities on intra-urban densities in the urban area of Lyon in 1990, 1999 and 2006, and defining an evolution law over time for the coefficients of the model. The successive relax of the hypothesis of spatial homogeneity and monocentrism which characterize the Bussière model and the improvement of the transport cost measure (distance from the centre of the urban area, generalized time, gravity accessibility to jobs) give good static results but do not allow for predicting the evolutions of the population densities at the district level. The selective movements of peri-urbanization and return to the centre that were stressed during this short time are far from being explained by the evolution of accessibility to the centre or to jobs in the urban area. The distribution of densities in this monocentric city depends not only on the accessibility to jobs but also appear to be structured by the centrality and the distribution of the social and spatial amenities, which in part result from the urban policy and the macro-agents decisions.

(pdf and official link)